WARSAW, DEC. 1 -- The failure of a national referendum to win a popular mandate for economic and political reforms here has confronted the government of Gen. Wojciech Jaruzelski with its most familiar and seemingly intractable political problem: the absence in Poland of a political constituency willing to back his attempts at liberalization.

Since announcing broad plans for political and economic change last month, Jaruzelski has seen the political foundation needed to launch such a program slowly crumble. Opposition to the proposal has emerged within the Central Committee of the Polish United Workers' Party -- the country's ruling communist party -- weakening the political platform.

Also, the apparent moderating of Mikhail Gorbachev's reform drive in the Soviet Union has raised questions about whether Moscow will stand behind Jaruzelski's "radical curing" of Poland.

Now, the unprecedented failure of the communist leadership to persuade more than 46 percent of the electorate to vote for its referendum propositions has battered any hopes Jaruzelski had of building a mass political movement. At the same time, the result has made clear that Poles are not ready to accept the price increases and other austerity measures that were a key part of the plan.

As a result, Poland's ruling general may be forced to continue overseeing the half-implemented, half-thwarted policies that have characterized his government since 1982 and that he vowed to leave behind in the "second stage of reform" this year. Without public support, with uncertainty in Moscow and with his party's conservatives on the offensive, Jaruzelski may simply be hemmed in.

"The authorities didn't get the vote of confidence that they desperately needed," said Janusz Onyskiewicz, spokesman of the banned Solidarity union, which advised Poles to ignore the plebiscite. "The question now is what sort of reform will they come out with, whether it will now be half-hearted."

If the impetus for dynamic change here is lost, the result could chill programs around Eastern Europe and become a significant blow to Gorbachev. In the last year, Jaruzelski had emerged as the strongest ally of the Soviet leader and the sponsor of the most radical reform in a region where conservative communists of the Brezhnev era still predominate.

Although government officials have insisted that the reform will continue, Polish political analysts say the authorities will have little choice but to back down from the doubling of basic food prices and tripling of rents and utility charges announced for next year.

While more modest price increases are negotiated with official unions, the Central Committee next week is to consider whether to change the modest package of political reforms.

The Politburo announced tonight that the results would require the party and legislature to "modify" the programs, "especially in their methods of implementation," said state television.

To a certain extent, several analysts said, the referendum may have helped the communist leadership by allowing it to show responsiveness and flexibility in the face of widespread public panic and discontent over the price rises that was evident well before the voting.

In this sense, the public announcement of unfavorable election results, a step unprecedented in a communist-ruled country, may have reflected the authorities' conviction that the battle to implement their economic policy had already been lost and the time had come to make concessions to the public.

"What happened was a kind of civilized version of what happened in Poland before," when workers rioted against price increases, which were then revoked, said Andrzej Wroblewski, a prominent journalist. "Instead of waiting for an uprising, the authorities accepted defeat in the election."

Yet even if the referendum result proves tactically advantageous, Jaruzelski, 64, cannot avoid damage to his political prestige, analysts said. He identified himself with the referendum campaign and stumped hard for victory, appearing on television for an hour on the eve of the vote to answer the doubts of youthful critics.

"My doubts are, first and foremost, centered on whether society will be ready to support this program," Jaruzelski said at that meeting, adding that opposition of party conservatives was a lesser problem.

While both Polish and western analysts indicate that Jaruzelski remains firmly in control of the party, the referendum results may force him to make new concessions to party hard-liners, delaying or diluting key political and economic steps.

At the first part of the Central Committee meeting last week, Jaruzelski heard open opposition to some of the political reform, which envisions a decentralization of government power and a partial legalization of opposition in the form of debating clubs and other small associations.

"Some of our members are uneasy about what they see as the too-broad formula for pluralism proposed by the party," was the blunt summary of Edward Lukasik, the Poznan party leader.

More nettlesome for Jaruzelski than the party struggle, however, is the public opposition and indifference to his reform efforts -- now established as a public fact as well as an opposition theory.

The issue is at once paradoxical and frustrating from the official point of view. While conservative opposition within the party is predictable, the overwhelming majority of Poles who backed Solidarity in 1980 are in some ways a natural clientele for Jaruzelski's new policies. Although some of the popular opposition can be attributed to the announced price increases, it is more difficult to explain why a third of this electorate failed to vote.

Government officials suggest that part of the trouble is that while almost all Poles support reform of the communist system in theory, many oppose practical measures that place their easy jobs at risk, link their pay to hard work, or place basic goods at realistic price levels.

Opposition leaders, however, argue that a more fundamental problem is a lack of confidence that Jaruzelski's government can implement reforms after suppressing Solidarity under martial law in 1981 and allowing the country to stagnate for five subsequent years.